nccthm – Another theorem environment

This pack­age's the­o­rems have two dis­tin­guish­ing char­ac­ter­is­tics.
First, the­o­rem num­ber­ing uses dy­namic coun­ters (spec­i­fied by
us­ing the dcounter pack­age, which
gives the user con­sid­er­able flex­i­bil­ity in count­ing styles.
Se­cond, the en­vi­ron­ment isn't de­fined as a trivlist (as LaTeX
the­o­rems are), which gives ex­tra flex­i­bil­ity in us­ing the
en­vi­ron­ment. In ad­di­tion, pa­ram­e­ter def­i­ni­tion is ex­plicit and
well-or­gan­ised, and there is a QED-sym­bol-plac­ing com­mand.